This invention relates to a scribe device for forming a scribe line on a surface of a workpiece of brittle material such as a plate glass, ceramics or the like.
Japanese Patent Non-examined Publication (Kokai) No. H09-25134 discloses a scribe device in which a scribe line is formed on a surface of a workpiece of brittle material by applying vibration thereto so that the workpiece can be broken along this scribe line. In this scribe device, an outside barrel of an air cylinder is fixed to a support portion and an inside barrel of the air cylinder is connected to one end of a piezo actuator. The other end of the piezo actuator is connected with a cutter retaining portion. The cutter retaining portion is slidably attached to the support portion through a slider mechanism. The cutter retaining portion is moved up and down in accordance with expansion and contraction of the piezo actuator and a scribe line is formed on a workpiece by vibration caused by the up and down movement of the cutter retaining portion.
However, such a scribe device has such a problem that resonance is liable to occur and a cutter is sprung up from the workpiece.
In view of the above, the inventor of the present invention had invented a scribe device prior to the present invention, in which a scribe device body is supported by a vibration damping member having resiliency (Japanese Patent Application No. H10-101967). By this, the problem of resonance of the scribe device is solved. However, because all (two) vibration damping members are spacedly arranged in the same direction as viewed from the center of gravity of a scribe body including a body, a holder and a cutter, they are supported in a so-called cantilever fashion. This gives rise to another problem in that the scribe body is swayed (or swung) drawing a circular arc pattern.
An object of the present invention is to provide a scribe device which is capable of absorbing resonance and which is not swung.
In order to solve the above problems, according to a first aspect of the present invention, there is provided a scribe device comprising a scribe body including an abutment member and a vibration generating member for applying vibrations to the abutment member; and a support portion for supporting the scribe body, wherein the scribe body is supported by the support portion through a pair of vibration damping members, the pair of vibration damping members being arranged in opposing relation in a direction orthogonal to a vibrating direction with the scribe body sandwiched therebetween.
By virtue of the above constitution, since the vibrations transmitted to the scribe body is damped by the vibration damping members which have resilient property, possibility of an occurrence of resonance can be reduced and the abutment member can be prevented from being sprung up from the workpiece, thus enabling to perform a stable scribing operation. Moreover, since the pair of vibration damping members are arranged in opposing relation in a direction orthogonal to the vibrating direction with the scribe body sandwiched therebetween, the scribe body can move back and forth stably without being swung drawing a circular arc pattern.
According to a second aspect of the present invention, there is provided a scribe device having further features, in addition to the features of the first aspect of the present invention, in which a center of gravity of the scribe device is located on or around a plane extending in the vibrating direction passing through a center of the pair of vibration damping member. By virtue of these features, the scribe body can be supported in a more stable manner.
According to a third aspect of the present invention, there is provided a scribe device having further features, in addition to the features of the first aspect of the present invention, in which at least two sets of the pair of vibration damping members are spacedly arranged in the vibrating direction. By virtue of these features, swaying of the scribe body can be prevented in a more reliable manner.
According to a fourth aspect of the present invention, there is provided a scribe device having further features, in addition to the features of the first aspect of the present invention, in which each of the vibration damping member is composed of a plate spring. By virtue of these features, the constitution can be simplified.
According to a fifth aspect of the present invention, there is provided a scribe device having further features, in addition to the features of the fourth aspect of the present invention, in which the plate spring extends not only in a direction orthogonal to the vibrating direction but also in an opposing direction of the pair of plate springs. By virtue of these feature, the moving locus of the scribe body can be more stabilized.
According to a sixth aspect of the present invention, there is provided a scribe device having further features, in addition to the features of the fifth aspect of the present invention, in which a center of the plate spring is fixed to selected one of the scribe body and the support portion and opposite ends thereof are fixed to the other. By virtue of these features, the scribe body can be supported stably.
According to a seventh aspect of the present invention, there is provided a scribe device having further features, in addition to the features of the sixth aspect of the present invention, in which bent portions are formed between the center of the plate spring and the opposite ends of the plate spring. By virtue of these features, the scribe body can be supported such that the scribe body can move in the vibrating direction smoothly.
According to an eighth aspect of the present invention, there is provided a scribe device having further features, in addition to the features of the first aspect of the present invention, in which the scribe device further comprises a slide mechanism, the slide mechanism including a guide and a slider supported by the guide for sliding in the vibrating direction, the slider being provided as the support portion. By virtue of these features, since the slider is movable by vibrations transmitted from the scribe body through the plate spring, a large reaction is not applied to the scribe body, thus enabling to reduce the possibility of an occurrence of resonance to the least possible extent.
According to a ninth aspect of the present invention, there is provided a scribe device having further features, in addition to the features of the first aspect of the present invention, in which the vibrating direction is generally perpendicular so that the abutment member is pressed against a surface of a workpiece by an own weight of the scribe body. By virtue of these features, the abutment member can be pressed by the own weight of the scribe device and without using any special biasing mechanism. Moreover, since a pressing force is applied to the abutment member so that the abutment member is pressed against the surface of the workpiece stably and the abutment member is not sprung up from the workpiece, chips can be prevented from occurring in the nearby area of the scribe line and a scribe line can be formed with a higher degree of precision.
According to a tenth aspect of the present invention, there is provided a scribe device having further features, in addition to the features of the first aspect of the present invention, in which the scribe body further includes a body and a holder supported by the body for sliding in the vibrating direction, the abutment member being retained by an end portion of the holder, the body and holder having receiving portions, respectively, which are in opposing relation in the vibrating direction, a piezo actuator being sandwiched, as the vibration generating member, between the receiving portions, the piezo actuator being cyclically expanded and contracted by being subjected to high frequency voltage, and the holder being biased by the pair of resilient members such that the receiving portion is pressed against the piezo actuator. By virtue of these features, the cyclic expansion and contraction of the piezo actuator can positively be transmitted to the abutment member in the form of vibration. Moreover, since the resilient members apply a pre-load to the piezo actuator, the abutment member can move following the vibratory motion of the piezo actuator and without receiving any affection of the reaction from the workpiece. Thus, a favorable scribing operation can be obtained.